feat(class-transformers): support array for EnumFallback decorator

algoan · Dec 21, 2023 · 6d649d5 · 6d649d5
1 parent 7213b43
commit 6d649d5
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Showing 3 changed files with 48 additions and 11 deletions.
diff --git a/packages/class-transformers/README.md b/packages/class-transformers/README.md
@@ -28,3 +28,21 @@ class User {
   public role?: UserRole;
 }
 ```
+
+It works with array too:
+```ts
+import { EnumFallback } from '@algoan/nestjs-class-transformers';
+
+export enum UserRole {
+  ADMIN = 'ADMIN',
+  READER = 'READER',
+}
+
+class User {
+  @EnumFallback({
+    type: UserRole,
+    fallback: (value: UserRole) => UserRole.READER // if an array element is not "ADMIN" or "READER", then the role will be "READER".
+  })
+  public roles: UserRole[];
+}
+```
diff --git a/packages/class-transformers/src/enum-fallback.decorator.ts b/packages/class-transformers/src/enum-fallback.decorator.ts
@@ -18,23 +18,31 @@ export interface EnumFallbackOptions<T> {
 /**
  * Return given literal value if it is included in the specific enum type.
  * Otherwise, return the value provided by the given fallback function.
+ * If the value is an array, the fallback function will be applied to each element.
  */
 export const EnumFallback = <T>(
   params: EnumFallbackOptions<T>,
   transformOptions?: TransformOptions,
-): PropertyDecorator => {
-  const { type, fallback } = params;
+): PropertyDecorator =>
+  Transform((transformParams) => {
+    const value = transformParams.value;
 
-  return Transform(({ value }) => {
-    // eslint-disable-next-line no-null/no-null
-    if (value === undefined || value === null) {
-      return value;
-    }
-
-    if (!Object.values(type).includes(value)) {
-      return fallback(value);
+    if (Array.isArray(value)) {
+      return value.map((element) => transformEnumValue(element, params));
+    } else {
+      return transformEnumValue(value, params);
     }
+  }, transformOptions);
 
+const transformEnumValue = <T>(value: T, { type, fallback }: EnumFallbackOptions<T>): T => {
+  // eslint-disable-next-line no-null/no-null
+  if (value === undefined || value === null) {
     return value;
-  }, transformOptions);
+  }
+
+  if (!Object.values(type).includes(value)) {
+    return fallback(value);
+  }
+
+  return value;
 };
diff --git a/packages/class-transformers/test/enum-fallback-decorator.test.ts b/packages/class-transformers/test/enum-fallback-decorator.test.ts
@@ -63,4 +63,15 @@ describe('EnumFallback Decorator', () => {
 
     expect(user.role).toEqual('WRITER');
   });
+
+  it('should return the fallback value for each invalid element if the property is an array', async () => {
+    class User {
+      @EnumFallback({ type: UserRole, fallback: () => UserRole.READER })
+      public roles?: UserRole[];
+    }
+
+    const user = plainToInstance(User, { roles: ['WRITER', 'ADMIN'] });
+
+    expect(user.roles).toEqual([UserRole.READER, UserRole.ADMIN]);
+  });
 });